Vinyl resin composition



Patented Jan. 5, 1943 zen-1,015 vnm. nssm courosmou Qnattlebonm, Jr.,and

Donald M. Young, Charleston, W. Va, asslgnors to Carbide and CarbonChemieais Corpoi-ation, a corporation of New York No DrawingsApplication August 2, 1940, erial No. areas;

11 Claims. (01. zoo-so) This invention is directed to improvements inthose vinyl resins which may be formed by the polymerization of vinylhalides or by the conjoint polymerization of vinyl halides with otherunsaturated and polymerizable compounds, examples of such compoundsbeing vinyl esters, il-unsaturated acids or their esters, lp-unsaturated ketones or aldehydes, and unsaturated hydrocarbons, suchas the butadienes or the styrenes. The invention is of particular meritwhen applied to the vinyl resins made by the conjoint polymerization ofvinyl chloride with vinyl esters of the lower aliphatic acids, as forinstance, vinyl acetate.

Resins of the type defined above are known and have been suggested fordifferent p pflses in the art. Among other characteristics, such resinsare distinguished by the property of thermoplasticity. In manyapplications this property is advantageous softened by heating, and inthis softened condition they may be molded into a variety of ob jects,they may be used as an adhesive for joinme or stiffening variousmaterials, or they may be applied as a coating by calendering to paperand like materials. Unfortunately, these artificial resins do notpossess unlimited stability in that the resins may be fectiveness butthey do not completely inhibit color development in the vinyl resinsupon heating to the temperatures required for their fabritowards heat.at temperaturesabove their softening points. Because of this, the use ofthese resins where a high degree of resistance to heat is required isnecessarily limited.

Decomposition of the resins at temperatures above their softening pointis usually initiated by the development of color in the resins. Thisstage is shortly followed by char-ring of the resins and theevolutionsof gaseous products of decomposition from the mass. .Becauseof the acidic nature of nets, it was postulated early in the developmentof these resins that the addition of basic substances to the resinsshould inhibit their thermal decomposition. Such proved to be the caseand a number of basic stabilizing agents have been suggested, amongwhich may be mentioned lead stearate, calcium stearate, calciumhydroxide, basic lead carbonate and triethanolamine. The most effectiveof such compounds from every viewpoint proved to be the basic metalsoaps of the fatty acids, and, of such compounds, lead and calciumstearates and oleates have come into very common use as stabilizingagents for these resins.

These compounds have proved stabilizing these resins against the secondeffective in yp of decomposition at least until color development 55 ofsalts or alcoholates, that the the decomposition prodcation. Inaddition, the alcoholates are watersoluble which tends to reduce theresistance to moisture of articles fabricated from the resins.

. According to this invention, a new class of heat stabilizing compoundshas been developed which, when incorporated in these resins, permitsthem to retain their pure white color, upon their fabrication intoarticles or coatings by the application of heat. The new heatstabilizing compounds also inhibit (to a marked degree) the actualdecomposition of the resin upon prolonged .heating. These compounds aremetal derivatives 'of 1,3 dicarbonylic substances, such as the beta-'diketones and the esters of the beta-ketoacids.

with aliphatic or aromatic alcohols, notably esters of acetoacetic acid.These compounds apparently are not simple alcoholates or salts but theyare believed to be complex co-ordination compounds. It is thought that aco-ordinate linkage is established between the metal-salt of" the enolform of the keto ester or diketone and the oxygen atoms of the remainingcarbonyl groups, the metal atom thereby becoming part of the two sixmember-ed rings. For calcium ethylacetoacetate, the structural formulaaccording to this hypothesis is as follows:

inc-o c-o can The properties of the metal derivatives of the,acetoacetic esters diiler so markedly from those chelate" structureshown above has been assigned to them. Analogous compounds are obtainedwith betadiketones.

Thus, unlike the alcoholates, these chelate derivatives are not readilyhydrolyzed by water; they are soluble in organic solvents but insolublein water; they possess low melting points, and in general exhibit theproperties typical of organic compounds rather than those of metallicsalts or allcoholates of organic compoimds.

The alkaline earth derivatives 01' acetoacetic esters, which areparticularly effective in preventing thermal discoloration of vinylresins containing polymerized vinyl halides, possess other propertieswhich make them more advantageous. Thus, they are insoluble in water anddo not reduce the resistance of coatings of the resins to transmission01' moisture. Also, in many cases they are compatible with the resinsand do not aflfect their clari y.

Typical examples of heat stabilizing compounds of alkaline earthderivatives of acetoacetic esters are calcium ethylacetoacetate, calciumbutylacetoacetates, calcium 2-ethylbutylacetoacetates, calciumz-ethylhexylacetoacetates, calcium oetylacetoacetates, calciumphenylacetoaceta calcilun benzylacetoacetates, and the correspondingcompounds of barium, strontium and magnesium. These compounds may bemade by heating the acetoacetic esters with the alkaline earth metalsuntil evolution of hydrogen ceases and, if desired, in the presence ofinert diluents, such as benzene, toluene or naphthalene. Ammonlacalsolutions of salts oi these metals will also react with acetoaceticesters to give the desired compounds.

The amounts of the alkaline earth derivatives to be incorporated withthe vinyl resins for inhibiting their thermal discoloration is small andthe most eirective amounts are from 0.5% to 5% by weight of the resins.It has been found that the resistance or the resins to development ofcolor on heating can be further increased by adding to the resin veryabout 0.02% to 0.1% by weight. of alkyl or aryl tin oxides or salts oforganic acids, such as dibutyl tin diacetate, dibutyl tin dilaurate. anddibutyl tin oxide along with the alkaline earth small amounts,

metal derivative of the acetoacetic ester. Traces o1 cadmimn or leadsalts, such as cadmium or lead steal-ates, also have a similar efiect.

The following examples will illustrate the invention in detail:

EMTIZPIC 1 Samples of a resin formed by the coniointpolya color muchless intense than that developed in -the other samples in this stringenttest.

It was-noticed that the amount of water absorbed in a given test periodby the resin containing 1% by weight or calcium ethylacetoacetate wasabout one-half as much as that absorbed by the sample containing 1%calcium methylate.

. vinyl chloride with Example 2 Example 3 Two paper coating compositionscomprising a conjoint polymer of vinyl chloride with vinyl acetate wereformulated containing in one case 1% by weight of calcium stearate andin the other 1% calcium ethylacetoacetate and 0.05% dibutyl tindlacetate. Both compositions were applied to paper by calendering attemperatures of about 0. to C. The coating containing calcium stearatewas yellow to tan in color but the coating containing the calciumethylacetoacetate and the tin compound remained practically white.

The uses and modifications ot the invention will be apparentandthese areincluded within the scope of theinvention as defined by the appendedclaims.

We claim:

l. Acomposition resistant to the discoloring eflects of heat comprisingan artificial thermoplastic resin, including a vinyl halide polymerizedtherein, intimately combined with a small amount of a basic metalchelate derivative of a 1,3-dicarbonylic compound capable of keto-enoltautomerlsm.

-2. A composition reslstantvto the discoloring eiiects of heatcomprising an artificial thermoplas tic resin, including a vinyl halidepolymerized therein, intimately combined with a small amount 01 a basicmetal chelate derivative of an ester of a 'beta-ketoacid capable oi.keto-enol tautomerism.

.3. A composition resistant to the discoloring effects of heatcomprising an artificlal thermoplastic resin, including vinyl chloridepolymerized therein, intimately combined with a small amount of analkaline earth metal chelate derivative of an acetoacetlc ester.

4. A composition resistant to the discoloring effects of heat comprisingan artificial thermoplastic resin, including vinyl chloride polymerizedtherein, intimately combined with a small amount or a calcium chelatederivative of an acetoacetic 5. A composition resistant to thediscoloring eflects of heat comprising an artificial thermoplasticresin, including vinyl chloride polymerized therein, intimately combinedwith a small amount of an alkaline earth metal chelate derivative of anacetoacetic ester of an aliphatic alcohol.

6. A composition resistant to the discoloring eil'ects of heatcomprising plastic resin, including vinyl chloride polymerized therein,intimately combined with a small amount of an alkaline earth metalchelate derivative of an acetoacetic ester and a lesser amount of one orthe group consisting of alkyl and aryl tin salts of organic carboxylicacids.

7. A composition resistant to the discoloring eilects of heat comprisinga conjoint polymer of vinyl acetate intimately combined with a smallamount of a calcium chelate derivative of anacetoacetic ester of analiphatic alcohol.

an artificial thermo-E 8. A composition resistant to the discoloringeffects of heat comprising a conjoint polymer of vinyl chloride withvinyl acetate intimately combined with a small amount of a calciumchelate derivative 01 an acetoacetic ester of an aliphatic alcohol and alesser amount of one of the group consisting of alkyl and aryl tin saltsof organic carhoxylic acids.

9. A composition resistant to the discoloring effects of heat comprisinga conjoint polymer of 10 vinyl chloride with vinyl acetate intimatelycombined with a small amount of calcium ethylacetoacetate.

acetate.

WILLIAM M. QUA'I'ILEBAUM, JR. DONALD M. YOUNG.

